1. Field of Invention
The present invention relates to a display driving circuit, and more particularly, to a display driving circuit that is serially connected.
2. Description of Related Art
In recent techniques, when the Liquid Crystal Display (LCD) panel is fabricated, the Low Temperature Polycrystalline Silicon (LTPS) technique is commonly used to fabricate the Thin Film Transistor (TFT), which is disposed on a glass substrate. However, the yield rate of the fabrication process of the driving circuit which is used for driving each pixel, including the scanning driving circuit and the data driving circuit, is not yet fully stable when such fabrication process is applied. In other words, when this method, currently the most commonly used method, is used to fabricate the LCD panel, serious problems happen, such as an unstable yield rate of the driving circuit.
As shown in FIG. 1, the driving circuit of the LCD panel is usually comprised of a plurality of serially connected shift registers. Herein, each of the shift registers 102, 104, and 106 is one of the components that respectively constitute the driving circuit 10. When each of the pixels on the LCD panel is being driven, a start signal ST is first transmitted to the shift register 102. After a predetermined period of time (normally a clock signal) has passed, the start signal ST is transmitted from the shift register 102 to the shift register 104. Similarly, the start signal ST is sequentially transmitted from the shift register 104 to the shift register 106 and other subsequent shift registers in the same manner. Further, each of the pixels is driven by the driving line 112, 114, and 116, which is electrically coupled respectively to the output terminal of the shift register 102, 104, and 106.
Since the physical circuit of the driving circuit 10 is configured by a plurality of serially connected shift registers, if the circuit of one of the shift registers has some problem, it affects the operation of the subsequent shift registers. In this case, the problem of the unstable yield rate of the driving circuit due to the LTPS fabrication process becomes a problem that urgently needs to be addressed.